Texas Instruments TLV431ACDBVRG4

Overview

TLV431ACDBVRG4 from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±1% initial tolerance at 25°C, 0.25 Ω typical dynamic impedance, and operation down to 1.24 V cathode-anode voltage - used as an integrated reference in isolated flyback secondary-side regulation, Zener replacement, and voltage monitoring circuits.

For engineers reviewing the TLV431ACDBVRG4 datasheet, TLV431ACDBVRG4 pinout, TLV431ACDBVRG4 application, or TLV431ACDBVRG4 equivalent, key selection considerations include reference accuracy over temperature (±4 mV from 0°C to 70°C), minimum cathode current (80 µA typical), SC-70 package footprint, and open-loop comparator functionality with built-in 1.24 V threshold.

Technical Context

The TLV431ACDBVRG4 implements a bandgap-referenced error amplifier driving a Darlington sink output stage, enabling precise shunt regulation via external resistor feedback between cathode and reference pins. Its internal architecture supports both closed-loop regulation (e.g., optocoupler-coupled SMPS feedback) and open-loop comparator operation with integrated reference.

It operates with cathode-anode voltage (VKA) from 1.24 V to 6 V and requires ≥80 µA cathode current for stable regulation. Temperature drift is specified at ±4 mV over 0°C to 70°C (TLV431AC grade), and dynamic impedance remains ≤0.4 Ω across 0.1 mA–15 mA cathode current range.

Key Specifications

Pinout & Package

TLV431ACDBVRG4 uses the SC-70 (DCK) 6-pin package with exposed substrate pad. Pin 2 is substrate-connected and must be tied to anode or left floating per TI design guidance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar shunt regulator applications.

Compared with TLV431BIDBVR, TLV431ACDBVRG4 trades 0.5% accuracy for lower cost and sufficient stability in non-critical feedback paths; versus TLVH431ACDBVR, it offers smaller SC-70 size and lower minimum operating voltage but cannot regulate above 6 V or sink >15 mA.

Availability

TLV431ACDBVRG4 is available at Aetrix Electronics and suitable for isolated flyback power supplies, voltage monitoring systems, and Zener-replacement circuits requiring stable component supply, consistent parametric performance, and long-term manufacturability.

Supply support for TLV431ACDBVRG4 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company specializing in analog, embedded processing, and power management technologies, with leadership in precision analog ICs for industrial, automotive, and communications markets.

The TLV431x family was designed specifically for low-voltage, high-accuracy shunt regulation and integrated reference applications - targeting space-constrained, cost-sensitive power and monitoring systems where traditional TL431 variants are oversized or over-specified.

FAQ

What is the reference voltage tolerance of TLV431ACDBVRG4 at 25°C?

The TLV431ACDBVRG4 has a reference voltage tolerance of ±1% at 25°C, corresponding to a V_REF range of 1.228 V to 1.252 V. This specification is confirmed in Section 5.6 of the official Texas Instruments datasheet SLVS139Z. The 'A' suffix denotes the 1% grade, and the 'C' indicates commercial temperature range (0°C to 70°C). TLV431ACDBVRG4 maintains this accuracy without external calibration.

Can TLV431ACDBVRG4 operate with a cathode-anode voltage below 2.5 V?

Yes, TLV431ACDBVRG4 is explicitly designed for low-voltage operation and functions down to 1.24 V cathode-anode voltage (V_KA). Unlike the TL431 (2.5 V reference), the TLV431ACDBVRG4's 1.24 V internal reference enables direct regulation of 1.8 V, 2.5 V, and 3.3 V rails. Its minimum operating V_KA is defined by the reference voltage plus headroom for internal transistor saturation - verified in TI's recommended operating conditions table.

What is the SC-70 package pin configuration for TLV431ACDBVRG4?

TLV431ACDBVRG4 uses the SC-70 (DCK) 6-pin package: Pin 1 = CATHODE, Pin 3 = REF, Pin 6 = ANODE, Pins 4 and 5 = NC (no connect), and Pin 2 = substrate (must connect to ANODE or leave open). This mapping is documented in Figure 4-5 and Table 4-1 of the SLVS139Z datasheet. The substrate pin is electrically isolated from all other terminals and requires explicit handling per TI layout guidelines.

How does TLV431ACDBVRG4 behave in open-loop comparator mode?

In open-loop mode, TLV431ACDBVRG4 functions as a comparator with integrated 1.24 V reference: when voltage at the REF pin exceeds V_REF, the CATHODE sinks current; otherwise, it remains high-impedance. It delivers fast response with no external reference needed, and output low is ~1 V while high is pulled to V_KA. This behavior is validated in Section 7.4.1 and Figure 8-2 of the datasheet, confirming TLV431ACDBVRG4's dual-role capability.

Is TLV431ACDBVRG4 pin-compatible with TLV431BIDBVR?

Yes, TLV431ACDBVRG4 and TLV431BIDBVR share identical SC-70 (DCK) package, pinout, and terminal functions - both use Pin 1 (CATHODE), Pin 3 (REF), Pin 6 (ANODE), and substrate Pin 2. The only functional difference is reference tolerance (±1% vs ±0.5%). No PCB changes are required when substituting TLV431ACDBVRG4 for TLV431BIDBVR, though system-level accuracy may vary based on the tighter tolerance of the 'B' variant.